Scraper for concrete conveyor belt

ABSTRACT

A scraper assembly used for removing residual concrete from a concrete conveyor belt, following removal of most of the concrete therefrom. A scraper blade is positioned against and substantially normal to the plane of the belt and substantially transverse thereto. The blade is constructed of a hard material such as carbide steel. A holder is provided for the scraper blade and the scraper blade is biased with pressure against the outer surface of the conveyor belt so as to substantially remove all the residual concrete therefrom.

atent 3,795,308

' 1 Mar.5,1974

[54] SCRAPER FOR CONCRETE CONVEYOR 873,418 7/1961 Great Britain 198/230BELT 1,227,384 1/1964 Germany 198/230 [75] Inventor: Robert F. Oury,Elmhurst, Ill.

Przmary Examiner-Even C. Blunk [73] Assignee: Rotec Industries, Inc.,Elrnhurst, 111. Assistant E -w, S t Carson [22] Filed: Aim 11, 1972Attorney, Agent, or FirmMolinare, Allegretti, Newitt & Witcoff [21]Appl. No.: 242,971

[52] U5. Cl. 198/230 [57] ABSTRACT [51] Int. Cl. B65g 45/00 A scraperassembly us d f r m ving residual con- [58] Field of Search 198/188, 230Crete m a concrete nv y r b l foll wing removal of most of the concretetherefrom. A scraper [56] Reference Cited blade is positioned againstand substantially normal to UNITED STATES PATENTS the plane of the beltand substantially transverse thereto. The blade is constructed of a hardmaterial such as carbide steel. A holder is provided for the scraperblade and the scraper blade is biased with pressure against the outersurface of the conveyor belt 1,975,591 10/1934 Sinden 198/230 2,393,7241/1946 Vickers.....

704,977 7/1902 Taylor 1,875,442 9/1932 Greg.....

2,885,069 5 1959 Bowen 198/230 so as to substantially r m a th r sidualconcrete FOREIGN PATENTS OR APPLICATIONS therefrom" 1,075,502 7/1967Great Britain 198/230 5 Claims, 3 Drawing Figures PAHENTEU 5'9743.795.308

oooooogjggo o oooo I SCRAPIER FOR CONCRETE CONVEYOR BELT BACKGROUND OFTHE INVENTION FIELD OF THE INVENTION AND DESCRIPTION OF THE PRIOR ARTThis invention relates to a scraper blade assembly for removingsubstantially all of the residual concrete from a concrete conveyor beltafter the bulk of the concrete has been directed from the belt to aplace of use.

Belt type conveyors for carrying materials such as concrete, gravel,sand and like materials have been known and used for several years, inthe construction business. Typical of such concrete conveyors are thosefound in Oury et al. U. S. Pat. No. 3,151,732, Oury U. S. Pat. No.3,171,534, and Oury U. S. Pat. No. 3,203,538. Another specific exampleof such a belt type concrete conveyor is that shown in my U. S. Pat. No.3,590,983.

Referring specifically to my U. S. Pat. No. 3,590,983, a diagonallymounted blade bears against the upper surface of the belt conveyor atthe desired position for discharging the concrete from the conveyor to aplace of use. Although the assembly substantially removes or wipes thegreat majority of the concrete from the belt, the belt wears quickly sothat within a short period of time streaks of unremoved or residualconcrete begin to show on the carrying surface of the belt after thebelt passes the normal concrete discharge position. Although, in myconcrete conveyor the frame for the ap' paratus has been specificallydesigned to prevent concrete from building up on it, itis neverthelesshighly desirable to substantially reduce the amount of residual concretefrom collecting on the frame, adding to the weight of the equipment,creating an unsightly condition, and even possibly adversely affectingthe operation of the equipment. It has therefore been found to bedesirable to remove substantially all the residual concrete from thebelt, following discharge of the bulk of the concrete from the belt.

Although the concrete conveyor in my U. S. Pat. No. 3,590,983 does notshow a scraper assembly for removing residual concrete from the belt,belt scraping or cleaning blades for removing residual concrete fromconveyor belts are known. One such scraper blade was constructed with ascraper blade made from a relatively soft material, such as ordinarysteel, in order to avoid gouging and the forming of grooves in the belt.However, when such a soft scraper blade was used, it was found that thematerial being scraped, such as the aggregate in the concrete, wore thesoft blade so that it had to be replaced rather frequently. Also, withsuch a soft scraper blade, the wearing of the blade was uneven andcaused grooves to start forming in the concrete conveyor belt. Thus,adverse effects were created not only on the scraper blade, but also onthe conveyor belt. Furthermore, with such a soft scraper blade, it wasfound that a relatively high force or pressure was needed for the bladeto bear against the belt in order to properly clean the conveyor belt ofthe residual concrete.

SUMMARY OF THE INVENTION It is therefore an important object of thisinvention to provide an improved scraper assembly for substantiallyremoving residual concrete from a belt type concrete conveyor whereinthe disadvantages of prior art scraper assemblies are substantiallyavoided.

It is also an object of this invention to provide an improved scraperassembly for removing residual concrete from a concrete conveyor beltwhere the scraper blade is constructed of a material which is harder notonly than the belt, but also harder than the material being scrapedtherefrom, such as concrete containing aggregate.

It is a further object of this invention to provide an improved scraperassembly for removing residual concrete from a concrete conveyor beltwherein the scraper blade is constructed of a carbide steel.

It is still another object of this invention to provide an improvedassembly for scraping concrete from a conveyor belt wherein both thescraper blade and the concrete conveyor belt have an extended life bythe use of a scraper blade which is harder than the aggregate in theconcrete.

It is still a further object of this invention to provide a scraperblade assembly used for cleaning residual concrete from a conveyor beltwherein the scraper blade assembly is characterized by its simplicityand economy of construction and effectiveness in use.

Further purposes and objects of this invention will appear as thespecification proceeds.

The foregoing objects are accomplished by providing a scraper assembly,useful for substantially removing residual concrete or like material,from a conveyor belt wherein the assembly includes a scraper blade whichextends transversely across the outer surface of the conveyor belt, theblade being constructed of a material which is harder than the materialbeing scraped from the belt, a holder for mounting the blade, and meansfor biasing the holder and thereby for pressing the blade against theouter surface of the belt for substantially removing residual concretetherefrom.

BRIEF DESCRIPTION OF THE DRAWINGS A particular embodiment of the presentinvention is illustrated in the accompanying drawings wherein:

FIG. 1 is a side elevational view of a conveyor assembly using myimproved assembly for substantially removing the residual concrete fromthe belt conveyor;

FIG. 2 is an enlarged detailed side elevational view of my improvedscraper assembly as used in the embodiment of FIG. 1; and

FIG. 3 is a further enlargement of the embodiment of FIG. 2 showing thescraper blade and the holder therefor in greater detail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, aconcrete conveyor assembly 10 is shown wherein my improved scraperassembly, generally 12, is used. It is to be understood that the scraperassembly 12 may be used with other types of conveyors useful forconveying materials such as concrete, sand and gravel.

The concrete conveyor 10 shown in FIG. I includes a horizontallyelongated support frame 14, with a pair of wheel support assemblies 16mounted at the opposite ends of the frame 14 for movably supporting theconveyor 10. The elongated frame 14$ carries a driven conveyor belt 118which carries concrete from an inlet position to a discharge positionand is the belt which is cleaned by the scraper assembly 12. A hopper 20is mounted at the inlet end 22 of the conveyor assembly 10. The hopper20 receives concrete from a concrete supply and the concrete isdischarged onto the moving belt 18. The belt 18 is generally supportedin a U- shaped position until it reaches the moving plow 24, where theplow discharges the concrete laterally from the conveyor to a place ofuse. Although the plow assembly 24 cleans substantially all of theconcrete from the belt 18, a residual amount of concrete will commonlyremain on the outer surface of the belt 18. The belt passes around apulley 26 at the outer end 28 of the'frame 14 for returning to thehopper 20. Without having the scraper assembly 12, any residual concreteon the belt 18 could drip from the belt in returning to the hopper 20.This concrete could harden on the frame 14 adding to its weight andcreating an unsightly appearance. Hardened residual concrete on any partof the conveyor 10 could also cause mechanical problems. Although theconveyor 10 shown is designed to significantly reduce such concretebuild-up, it is nevertheless highly desirable to position the scraperassembly 12 at the outer end 28 of the frame 14 for removingsubstantially all of the residual concrete from the carrying surface ofthe belt 18.

Referring to FIGS. 2 and 3, the scraper assembly 12 is shown in greaterdetail. The scraper assembly 12 is positioed in close proximity to thepulley 26 and the blade 30 bears against the outer or carrying surfaceof the belt 18 in its return path of travel on the frame 14. Theparticular location of the scraper assembly 12 is preferred because thebelt 14 is supported by the pulley 26 and thereby provides resistance tothe force or pressure of the blade 30 bearing against the outer surfaceof the belt 18 so as to provide a thorough cleaning of the belt.

In addition to the blade 30, the scraper assembly 12 includes a holder32 for the scraper blade 30, a pair of support arms 34 for the holder,and a spring member 36 for biasing the holder 32 and thereby the blade30 with pressure against the outer surface of the belt 18 to accomplishthe desired cleaning thereof.

The support arms 34 are spaced from each other on opposite sides of thebelt 18 and are pivotally mounted on each of a pair of brackets 38 whichare rigidly secured to spaced parts of the frame 14 of the conveyorassembly 10. The inner or pivoted ends of the arms 34 are pivotallysupported on a pivot plate 40 while the outer ends of the arms arerigidly secured to the opposite lateral ends of the holder 32. As shownin FIG. 3, suitable fasteners, as screws, 42 are used to secure theouter or free ends of the support arms 34 to the opposite ends of theholder 32.

The holder assembly 32 includes two interengaging extruded aluminummembers 44 and 46. The larger or main extruded member 44 has a stepportion 48 which receives or engages the smaller extruded member 46. Thescraper blade 30 is rigidly held or captured between the extrudedmembers 44 and 46 which function as jaws to hold the blade 30 securelyin place. Suitable bolts 50 and nuts 52 hold the two members 44 and 46together to mount the blade 30 in place in the holder 32. Normally, theblade 30 bears substantially perpendicularly against the outer surfaceof the belt 18. Desirably, an apron 54, made of a suitable flexiblematerial, such as rubber, is rigidly secured to a lower elongated lip ofthe extruded member 44 for catching residual concrete scraped from thebelt 18 and for directing the same to a location away from the apparatus10. The holder section 44 and 46 are sloped downwardly and outwardly,relative to the position of the blade, so as to shed any residualconcrete particles that happen to bypass the scraper 30 and fall fromthe belt 18.

The scraper blade 30 itself is an important part of the invention. Theblade generally constitutes a flat, elongated piece of carbide steelhaving ground radius at its outer edge which bears against the belt 18,such radius being preferably ground to provide a parabolic edge. Thecarbide steel used is preferably a tungsten carbide blade having ahardness of at least 90 92 Rockwell A. The type of steel used forthescraper blade may be the same type and grade of steel that is used fortire studs, snow plow scrapers, and the like. Although the specificmaterial used for making the blade can be varied, it is important thatthe material used to make the blade is harder than the component partsof the concrete, primarily, the aggregate. With the carbide blade, ithas been found, contrary to previous beliefs, that the blade does notbecome worn from contact with the aggregate, and neither the blade northe belt have been found to develop grooves therein from excessivewearing of the blade. Thus, it is believed that any wearing occurs onthe aggregate and not on the blade.

Referring to FIG. 2, the tension of the spring member 36 may be adjustedby use of an adjusting bar 56. Each spring member 36 is held between asupport arm 34 and the top of the frame 14 of the conveyor assembly 10.The lower end of the spring 36 is detachably received on the undersideof the arm 34 at a point intermediate the pivot point of the arm 34 andthe holder 32 at the outer end of the arm 34. The upper end of thespring 36 is received in an aperture in the vertically elongatedadjusting bar 36. The upper ends of the adjusting bars 56 areinterconnected by a rigid cross bar 58. A plurality of vertically spacedapertures 60 are provided in the adjusting bar 56 and these apertures 60receive a hair pin 62 which engages the top side of a section of theframe 14. By varying the location of the hair pin 62 in the verticallyspaced apertures 60, the tension of the spring 36 may be varied betweendesired limits. it has been found that a tension of 25-50 pounds on eachside of the holder provides advantageous results. The springs 36 act tobias the arms 34 upwardly so that the scraper blade 30 bears withsuitable pressure against the belt 18 to accomplish substantial removalof residual concrete from the belt. The scraped concrete is therebydiverted as, by the apron 54, to a location away from the conveyorassembly.

The described scraper blade does not significantly wear and any wearwhich does occur is believed to be with the material being scraped, thatis, the concrete, as opposed to the blade itself. Such reduction orelimination of blade wear results in the avoidance of grooves developingin the scraper blade and the conveyor belt is not damaged or gouged.Furthermore, by avoiding grooves developing in the scraper blade, theamount of pressure required to clean and wipe the conveyor belt isreduced.

While in the foregoing there has been provided a detailed description ofa particular embodiment of the present invention, it is to be understoodthat all equivalents obvious to those having skill in the art are to beincluded within the scope of the invention as claimed.

What I claim and desire to secure by Letters Patent 1. A scraperassembly for substantially removing residual concrete from a movingconcrete conveyor belt, said assembly comprising, in combination, asingle blade only positioned substantially normal to said belt and atsubstantially right angles to the longitudinal axis of the direction ofmovement of said belt, said blade being fixed both longitudinally andtransversely of said longitudinal axis of said belt, and being movablesubstantially only in a direction normal to the surface of said belt,said blade being constructed of tungsten carbide steel of at least 90Rockwell A hardness, a pulley around which said belt passes, said bladebearing against the outer undersurface of said belt and being locatedlongitudinally from but in close proximity to the location of saidpulley, means for holding said blade, means for biasing said bladeagainst said belt with sufficient pressure for accomplishing the desiredremoval of residual concrete therefrom, said pulley providing resistanceto said biasing pressure, and means on said blade holding means havingdownwardly and outwardly inclined portions for directing scrapedresidual concrete to a location remote from said assem- 6 bly.

2. The apparatus of claim 1 wherein said holding means includes firstand second interengagin g elements for holding said blade therebetween,said downwardly and outwardly inclined portions being defined on saidelements.

3. The assembly of claim 1 including a frame, a pair of spaced armspivotally mounted on said frame, said spaced arms having free ends andsaid holding means are connected to said free ends, and said biasingmeans comprises spring means interconnected between said arms and saidframe for biasing said blade against said belt.

4. The apparatus of claim 3 including means for adjusting the tension ofsaid spring means to attain the desired pressure sufficient foraccomplishing removal of said residual concrete from said belt.

5. The apparatus of claim 1 wherein said blade includes an edge bearingagainst said belt, said edge having a substantially parabolic shape incross section.

1. A scraper assembly for substantially removing residual concrete froma moving concrete conveyor belt, said assembly comprising, incombination, a single blade only positioned substantially normal to saidbelt and at substantially right angles to the longitudinal axis of thedirection of movement of said belt, said blade being fixed bothlongitudinally and transversely of said longitudinal axis of said belt,and being movable substantially only in a direction normal to thesurface of said belt, said blade being constructed of tungsten carbidesteel of at least 90 Rockwell A hardness, a pulley around which saidbelt passes, said blade bearing against the outer undersurface of saidbelt and being located longitudinally from but in close proximity to thelocation of said pulley, means for holding said blade, means for biasingsaid blade against said belt with sufficient pressure for accomplishingthe desired removal of residual concrete therefrom, said pulleyproviding resistance to said biasing pressure, and means on said bladeholding means having downwardly and outwardly inclined portions fordirecting scraped residual concrete to a location remote from saidassembly.
 2. The apparatus of claim 1 wherein said holding meansincludes first and second interengaging elements for holding said bladetherebetwEen, said downwardly and outwardly inclined portions beingdefined on said elements.
 3. The assembly of claim 1 including a frame,a pair of spaced arms pivotally mounted on said frame, said spaced armshaving free ends and said holding means are connected to said free ends,and said biasing means comprises spring means interconnected betweensaid arms and said frame for biasing said blade against said belt. 4.The apparatus of claim 3 including means for adjusting the tension ofsaid spring means to attain the desired pressure sufficient foraccomplishing removal of said residual concrete from said belt.
 5. Theapparatus of claim 1 wherein said blade includes an edge bearing againstsaid belt, said edge having a substantially parabolic shape in crosssection.